The highest common factor (abbreviated to HCF) is the largest number that goes into two or more subject-numbers. For example, the common factors of 40 and 16 are 2, 4 ...

Sometimes you are given numbers expressed as a product of prime factors. For example, 8 = 2 3 and 90 = 2 × 3 2 × 5. If you want to find the LCM and HCF in an exam, we can use prime factor form to ...